I have been wanting an E-Commerce Website to sell wallpapers online. My developer is in Janak Puri. More than six months have passed and my website is not complete.
Currently my website shows some error. You can see:-
divinefurnish.com
I have spent a considerable amount of money on this project. My developer is saying that it will take one more month to complete.
My question is that is it normal for a Website creation to take this long?

Well the total time duration for developing an E-Commerce Website depends upon the number of features that you want in your website.
For a normal single vendor E-Commerce Website it should not takes a developer and his team a duration of 1.5 to 2 Months (45 – 60 days) to develop a complete website. If your website is a multi vendor website then the duration will be of 2 to 2.5 Months (60 to 75 days) to develop the complete website. If you want some more moderately complicated features than any E-Commerce Website development project can take an extra time of at most one month. For even more complicated features the website may take more time.
But in your case I doubt that the features will be complicated enough to take more than 6 Months. Software development is a difficult task. It requires highly skilled professionals to create a single E-Commerce Website. There is a good possibility that your developer might not have the proper expertise to handle such a project. I will suggest you to give his that extra one months time that he is asking for (if he is not charging anything extra for it) and then switch to a better developer if you are not satisfied with his results.